Evacuator for cylindrical driers.



l a shears- SHEET gX/ 'Animer' Patented Mar. 5,1918.:

APPucATloN msn ^ue.|o. m1,'

- c. L. sT. CLAIR & 1.; H. HOFFMAN.

,EVACUATOR.FOR'CYLINDRICALPHIER n HOFFMAN. EVCUATQR FOB CYLINDRICALDRIERS.

. CLAIR a 1.

C. L. ST

"APPLICATION ILED AUG-MNHN.

' yPatented Ma1z-5V 1918. a sums-.SHEET a.

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' )brown emma L. sT. stm, or onEGoN CITY, onasoisr, AND JOHN n. HOFFMAN,or nANsv1LLE,`

VNEW

UNITED sTATns PATENT carica YORK.

EVACUATOR FOR CYLINDRICAI) DRIERS.

`Specification of Letters Patent.

Patented Mar. 5, 1918.

Appucaion mea August 1c, 1917. serial No. 135,608.

'To all whom 'it mayl concern.'

BeLjt vknown that we, CLYDE L. ST. 'CLAIR The invention relates to' thatclass of.

evacuators wherein the'water of condensation from the heatingagentstealn is re` moved from the interior of the drier body by theoperation of parts that are integral with is to remove this water of'condensation from the drier at higher speeds of revolution of the drierthan have hitherto beenv attainable with this type of evacuator, and itis related .particularly to the cylindrical driers used in the papermaking art. The meansemployed are simple, efficienty and durable.

` Referring to the draWings,-

Figure 1 is a longitudinal elevation show# ing in dotted outline theveinsk or channels a that are used to direct the water of condensationto one end of the drier, with a portion of the outer shell broken awayto show the spiral chambered section of the front end. Fig. 2 is alongitudinal section.

Fig. 3 is a longitudinal elevation showing the outside face of thedrier, with its two -journal heads and journals 9 and 10 and the drainor discharge pipe 4: leading from the left hand journal. Fig. 4 is anend view of the chambered end of the drier looking at it from the insideof the drier. Fig. 5 shows the ribs or veins at and the openings 6 intothe .outer groove of the spiral chamber. Fig. 7 is a top view of rib aand opening 6 into .outer groove of end chamber; the outer shell 1 hasbeen removed. Fig. 8 also shows'in Section the vein a and opening 6 intoouter grove of spiral chamber. Fig. 9 is an end view of drier showinghow the back head 3 is bolted to the drier shell.

There are several well known methods of taking the water of condensationout of the driers on a paper machine which work satisv factorily whenthe outer surfaces of the drying units are not traveling over 600 feetper minute. But the tendency -is toward increasthe drier and turn withit. Its objectl ing the speed of paper machines and 700 feet per minuteis now possible, with a prediction of 1000 feet per minute at no verydistant time. At some point 'between`600 and 700 feet per minute, thewater that has collected in the drier is held by centrif-` ugal forceagainst the inner wall and those evacuators which depend upon gravityalone are ineffectual under such conditions, as the force of gravitywill not cause the water to flow'to the outlet. And this presents onethe machine is increased and the usual fortyeight inch and sixty inchdiameter drying #units are caused to revolve faster. The driers fillwith water, thus interferin with the proper and economial heating o thedrier surface and taking more steam to dry a given quantity of paper.Another consideration of importance in this connection isr thatby thenecessary use of a larger amount of steam the pressure in the drier isincreased and this increases the back pressure on the engine, as exhauststeam direct' from the enginevisl principally employed in the dryingsystem, although live steam is also introduced when too 'much water hasaccuf .65 Y' of the main difliculties vwhen theV speed of'A mulatedinthe driers and itbecomes imperaj' tive to bring the. driers up to therequired temperature.- Thisof course, entails an '1ncreased cost forfuel, aside yfrom cutting down the. powerofthe' engine. Experience hasalso shown that the various forms of scoops, dippers and the likethat itis customary to bolt on the inside of the drier to the back drier headfrequently work loose,l

-break and cause constant trouble and expensive repairs. In this/respectit will be noted that in our device the`\iat spiral chamber forms partof the drier itself, Fi s. 1 and 6,' and cannot become loose or bro en;also that the veins or channels a are 'simply In the operation of ourdrier, steam enters through the hollow journal 9 of back -journal head3. The channels or veins a which. are simply' ribs or projectionsarranged as advancing open spirals on the inside Wall of the drier,Figs. 4 and 5, disposed as shown in Fig. l, guide and carry the Water ofcondensation, as the drier rotates, to the outer groove of the flatspiral chamber 2, ,Which comprises the front end of the drier shell 1,Fig. 2. At 'the chamber end of each vein, just Where it joins the oute'rgroove of the spiral chamber 2, there is .an opening 6, Figs. 1, 7 and8, through Which the. Water flows into the outer groove vent holesshould be located at 'that part ofl the groove which is closer thecenter as appears in Fig. 4. This flat spiral, formed b'y thecontinuouscurved Walls. b, Z2, is of very gradually changing i'adius, resulting in.but

slight pitch, so that while the centrifugal force of the rotating driertends to hold the Water inthe outer groove of the spiral, the force ofgravity and the effect of the spiral causes the Water to flow to thecenter pocket minute.

8 and thence it passes outvthe drain pipe 4. lSuch an evacuator, willempty the drier of all its Water of condensationup to a peripheral speedsaid spiral chamber. of nearly nine hundred feet per' We claim t- 1. Acylindrical drier shell or body, a fiat spiral chamber integral with thedrier body and forming one end thereof, a plurality of openings into theouter groove of this spiral chamber, a plurality ofopen spiral ribs,corresponding to the number 'of said openings, on the inner Wall of thedrier body, extending lengthwise thereof, the chamber end of each ribconnected with an opening into the outer groove of the spiral chamber,and an axial drain pipe from the spiral chamber.

2. A cylindrical drier shell, a flat s'iral chamber at'one end of thedrier she l, a plurality of open spiral ribs on the inner Wall of thedrier shell, extending lengthwise a .fiat spiral chamber at one endthereof,

a plurality of open spiral -ribs on the inner Wall of theV drier, thechamber end of each rib connecting With the outer groove ofthe saidspiral chamber. l

5. In a cylindrical drier, a iat spiral chamber a" )ne end thereof,vvith a plural-- ity of opel =ngs into the outer groove of the CLYDF. L.ST. CLAF.. JOHN H. HOFFMAN) l thereof and each connected with the outerl

